A known endoscope with panoramic view can be so altered by additions to both the objective and the eyepiece as to produce a contact endoscope of the kind specified. This gives the user the advantage that he does not need to purchase a complete contact endoscope, but can at slight expense make an existing endoscope usable for contact viewing. A large area can first be observed with low magnification, and then observation can be changed over to very high magnification on the microscopic or cellular scale over a smaller area, which is regarded as of further advantage for the examination. This enables pathological or tumour findings to be diagnosed immediately with direct observation, without requiring any ablation or operation (German OS 30 34 311.4).
With another contact endoscope the magnification can also be quickly altered. This is done by disposing a magnifying optical system with substantially higher magnification than the endoscope in a branched-off ray path which extends to an additional eyepiece. A slide is disposed transversely to the optical axis at the branching-off place, to act as an optical switch which in one operating position deflects the beam completely into the branched-off part, and in its other operative position contains a complete passage for the radiation to the other eyepiece. In this way two optical systems with different magnifications are always available and can, by very simply changing over the slide, be moved as required into the path of the beam (German OS 29 48 394.1).
Various biopsy devices for removing samples are also known. For instance, there is a tissue punch with a stripper for stripping off the tissue portions drawn in. As a result there is no need whatever to frequently pull out the punch for the removal of the punched-off tissue or bone. The pieces of tissue are accommodated in a tubular shank, where they are held fast. (German Utility Model 77 05 342).
This also ensures that the sample pieces in any case remain in the zone of the shank end, more particularly as a result of their being reliably released from the punching tool. For this purpose a spring-loaded stripper rod with a stripper is disposed at the distal end inside the punching tool. A bolt mechanism is also provided for releasing the spring-loaded stripper rod when this has reached its outermost distal position (German Utility Model 78 01 891.4).
Although it is now possible, using the already mentioned prior art contact endoscopes, to make an immediate diagnosis by direct observation of a pathological tumour tissue, there is nevertheless the need to cut a piece out of the observed zone to subject it to pathological examination.
However, this is impossible using the known biopsy tongs, since the spoon-like engaging parts of the tongs cannot be applied between the front lens of the contact endoscope and the tissue.
The invention relates to the problem of so improving the contact endoscope that a sample can be taken from the observed place even during observation, or at least immediately thereafter, without having to pull the contact endoscope out of the body.